What it is
A full-arch fixed bridge replaces every tooth in the upper or lower jaw with one bridge attached to implants.1 It is cleaned with daily brushing and flossing.1
- All-on-4. Four implants support the full arch.3 All-on-4 is a registered trademark of Nobel Biocare.2 The All-on-4 consensus (2017) lists an atrophic (thinned) upper or lower jaw as the main indication.3
- All-on-X. The X stands for a variable number of implants, such as four, five or six, chosen for the patient's anatomy.4 The ITI Group 2 consensus (2018) found that the literature supports various implant numbers for full-arch fixed bridges.5
Tilted implants
Some full-arch designs place implants at an angle (tilted implants).6 The ITI consensus states that intentionally tilted implants are indicated when appropriate conditions exist.5 A systematic review of 7,568 implants found no difference in failure or bone loss between tilted and straight implants, with very low quality of evidence.6
Results
An overview of 8 systematic reviews (2025) reported the following for All-on-Four.7
| Measure | Range across reviews |
|---|---|
| Cumulative implant survival | 94.8 to 99.3 percent |
| Mean bone loss | 1.1 to 1.5 mm |
None of the reviews found All-on-Four inferior to designs with more implants.7 Most of the reviews had high risk of bias, which the authors listed as a limitation.7
Teeth on the day of surgery
A provisional bridge can be attached on the day of surgery (immediate loading).3 The All-on-4 consensus states that immediate loading requires implant insertion torque over 35 Ncm and a rigid provisional that does not flex.3 The final bridge must be designed so it can be cleaned.3
Upkeep over the years
A systematic review of fixed full-arch bridges with at least 5 years of follow-up found that complications build up with time.8 The share of bridges free of any complication was 29.3 percent at 5 years and 8.6 percent at 10 years.8 The most common event was chipping or fracture of the veneering material.8 The authors noted these events may not cause failure of the implants or bridge but add repair time and cost.8
General information about dental implants. Treatment decisions are made with a licensed dentist.
Sources
- American Academy of Periodontology: Full Mouth Dental Implants. perio.org
- Nobel Biocare (manufacturer): Multi-unit Abutment. nobelbiocare.com
- Penarrocha-Diago M et al. Consensus statements on All-On-4 standard treatment. J Clin Exp Dent 2017. pubmed.ncbi.nlm.nih.gov
- AvaDent (manufacturer): The Clinician's Guide to All-on-X Implants. avadent.com
- Morton D et al. Group 2 ITI Consensus Report: Prosthodontics and implant dentistry. Clin Oral Implants Res 2018. pubmed.ncbi.nlm.nih.gov
- Apaza Alccayhuaman KA et al. Tilted vs straight implants supporting fixed prostheses: systematic review. Clin Oral Implants Res 2018. pubmed.ncbi.nlm.nih.gov
- Figueiredo CE et al. All-on-Four treatment concept: overview of systematic reviews. Oral Maxillofac Surg 2025. pubmed.ncbi.nlm.nih.gov
- Papaspyridakos P et al. Complications with fixed implant rehabilitations for edentulous patients. Int J Oral Maxillofac Implants 2012. pubmed.ncbi.nlm.nih.gov
